TWI452790B - Converting controller - Google Patents

Description

Conversion controller

The present invention relates to a conversion controller, and more particularly to a conversion controller having a protection output pin.

Please refer to the first figure for the circuit diagram of the QX9910 produced by QX Micro Devices Co., Ltd. for the LED driver circuit. The LED driving circuit includes a conversion circuit and a QX9910 controller 10 for driving a LED module 20. The conversion circuit includes an inductor L, a Schottky diode Z, a switch SW and a current detecting resistor R. The QX9910 controller 10 controls the on and off of the switch SW, so that the power of an input power source Vin is input to the conversion circuit and converted into an appropriate power source to drive the LED module 20 to emit light. In addition, an input driving circuit can be added, including an input resistor Rin, an input capacitor Cin, and an input Zener diode Zin. The input driving circuit is coupled to the input power source Vin to generate a power source VDD and is transmitted through a power pin VD to provide power required for operation of the QX9910 controller 10. A start pin EN of the QX9910 controller 10 is simultaneously coupled to the power pin VD. When the power supply VDD reaches a start level, the QX9910 controller 10 starts operating.

The QX9910 controller 10 includes a detecting resistor Rcs, a detecting capacitor Ccs, a comparator 2, an SR flip-flop 4, a driving circuit 6, a fixed off-time circuit OFT, and a reference voltage generator BG. The current detecting resistor R detects the current flowing through the LED module 20 when the switch SW is turned on and generates a current detecting signal Ifb. The detecting resistor Rcs and the detecting capacitor Ccs are coupled to the current detecting resistor R through a detecting pin CS to filter the current detecting signal Ifb and input the non-inverting input terminal of the comparator 2. The inverting terminal of the comparator 2 receives the reference level of 250 mV generated by the reference voltage generator BG, and generates a high-level output signal when the level of the current detecting signal Ifb is higher than 250 mV. One of the SR flip-flops 4 is coupled to the fixed off-time circuit OFT, a reset The terminal R is coupled to the output of the comparator 2, and the output terminal Q is coupled to the driving circuit 6. The driving circuit 6 is coupled to one of the control terminals of the switching switch SW and the fixed off-time circuit OFT through a driving pin DR. When the reset terminal 4 receives the high-level output signal of the comparator 2, the SR flip-flop 4 turns off the switch SW through the drive circuit 6, and the fixed-off time circuit OFT starts counting. When the changeover switch SW is turned off for a predetermined off time, the SR flip-flop 4 is triggered to re-energize the changeover switch SW. The predetermined cutoff time of the fixed cutoff time OFT is set by an RC circuit composed of a set resistor Rf and a set capacitor Cf via a cutoff time setting terminal TOF.

However, the QX9910 controller 10 does not have a protection mechanism and cannot be protected when there is any abnormality in the circuit. Moreover, the QX9910 controller 10 needs to communicate with other circuits by adding additional pins when it needs to be protected by other circuits (for example, a circuit that supplies an input power source Vin), and also because of the foot position. This increases the cost of controller packaging.

In view of the fact that the prior art conversion controllers are unable to protect against circuit anomalies and are also protected with other circuits, an additional foot is required to cause an increase in cost. The invention can not only provide protection for circuit abnormality through the multi-function pin mode, but also cooperate with other circuits to achieve more protection effect without increasing the cost of the conversion controller.

To achieve the above objective, the present invention provides a conversion controller including a power supply pin, a ground pin, at least one input pin, at least one output pin, at least one set pin, and an error generating circuit. The power pin is used to couple a power source to receive power required for operation, and the ground pin is coupled to ground. At least one input pin is for receiving an input signal, and at least one output pin is for outputting a signal. At least one set foot is used to set the operating parameters of the conversion controller. The error generating circuit is coupled to the at least one input pin and the at least one set pin to make the pin simultaneously serve as a protection output pin. Among them, the error generating circuit is rotating When the controller is in a protection state, the level of the protection output pin is adjusted to a protection logic level.

The above summary and the following detailed description are exemplary in order to further illustrate the scope of the claims. Other objects and advantages of the present invention will be described in the following description and drawings.

Please refer to the second figure, which is a circuit diagram of a conversion controller with a multi-function pin according to the present invention. The pin of the conversion controller includes a power pin VD, a ground pin GD, input pin I1, I2, output pin O1, O2, set pin S1, S2, wherein the input pin, output pin and setting The number of pins can be set according to the actual circuit requirements, and the number is not limited to a plurality. The power pin VD is coupled to a power source VDD for receiving power required for operation, and the ground pin GD is coupled to ground. Input pins I1 and I2 are used to receive input signals, and output pins O1 and O2 are used to output signals. The setting pins S1 and S2 are used to set the operating parameters of the conversion controller. The conversion controller further includes an error generating circuit including a protection unit PRO and a transistor switch M. One end of the transistor switch M is coupled to a protection output pin, and the other end is coupled to one of the power pin VD and the ground pin GD. In this embodiment, the ground pin GD. The protection output pin is a multi-function pin. Since the output pin of the conversion controller is used to control the switch in the conversion circuit, it should not be used as a protection pin at the same time. Therefore, it is selected from the input pin and the set pin. . In this embodiment, the multi-function pin is the set pin S1. In the normal operating state, the set pin S1 operates at the unprotected logic level, and in this embodiment the protection logic level is zero potential. The protection unit PRO causes the conversion controller to be in a protection state when the circuit is abnormal, and generates a protection signal Prot to the transistor switch M to turn on the transistor switch M. At this time, the level of the set pin S1 will be pulled to zero potential, that is, the protection logic level. The other circuit can be coupled to the set pin S1, and the protection program is simultaneously performed when the level of the set pin S1 is detected to be the protection logic level.

In order to avoid the preset protection logic level of the conversion controller and other circuits are used to determine the protection level setting, the protection output pin of the conversion controller may be externally connected with a logic level conversion circuit ST to adjust the protection logic level. As shown in the second figure, the logic level conversion circuit ST includes a transistor switch Mfa and a resistor Rfa. The transistor switch Mfa and the resistor Rfa are connected in series between the power source VDD and the ground. When the level of the set pin S1 is the protection logic level, the transistor switch Mfa is turned from off to off, so that the connection point of the transistor switch Mfa and the resistor Rfa generates a high level error signal Fail to other circuits.

Referring to FIG. 3, a circuit diagram of a conversion controller having a multi-function pin according to a first preferred embodiment of the present invention is used to control a conversion circuit to drive a LED module 120. The conversion circuit includes an inductor L, a Schottky diode Z, a switch SW, and a current detecting resistor R. The switching controller 100 controls the on and off of the switching switch SW, and inputs the power of an input power source Vin to the conversion circuit and converts it into an appropriate power source to drive the LED module 120 to emit light. An input driving circuit includes an input resistor Rin, an input capacitor Cin, and an input Zener diode Zin coupled to the input power source Vin to generate a power source VDD and provide switching control through a power pin VD of the conversion controller 100. The device 100 operates the required power. A startup pin EN of the conversion controller 100 is simultaneously coupled to the power supply pin VD. When the power supply VDD reaches a startup level, the conversion controller 100 starts operating.

The conversion controller 100 includes a detecting resistor Rcs, a detecting capacitor Ccs, a comparator 102, an SR flip-flop 104, a driving circuit 106, an error generating circuit, a fixed off-time circuit OFT, and a reference voltage generating The BG, wherein the error generating circuit comprises a protection unit 110 and a transistor switch 112. The detecting resistor Rcs and the detecting capacitor Ccs are coupled to the current detecting resistor R through a detecting pin CS to filter the current detecting signal Ifb generated by the current detecting resistor R and input the non-inverting input of the comparator 102. And the inverting terminal of the comparator 102 receives the reference signal Vr generated by the reference voltage generator BG. When the level of the current detecting signal Ifb is higher than the level of the reference signal Vr, the comparator 102 generates a high level output signal. One of the SR flip-flops 104 is coupled to the fixed end The stop circuit OFT, a reset terminal R is coupled to the output of the comparator 102, and an output terminal Q is coupled to the drive circuit 106. The driving circuit 106 is coupled to one of the control terminals of the switching switch SW and the fixed off-time circuit OFT through a driving pin DR. When the reset terminal R receives the high-level output signal of the comparator 102, the SR flip-flop 104 turns off the switch SW through the drive circuit 106, and the fixed-off time circuit OFT starts counting. When the switch SW is turned off for a predetermined off time, the SR flip-flop 104 is triggered to re-energize the switch SW. The predetermined cutoff time of the fixed cutoff time OFT is set by an RC circuit composed of a set resistor Rf and a set capacitor Cf via a cutoff time setting terminal TOF.

One end of the transistor switch 112 of the error generating circuit is coupled to the power pin VD, and the other end is coupled to the cutoff time setting terminal TOF. In this embodiment, the cutoff time setting terminal TOF is a multi-function pin. When the switching controller 100 operates normally, the protection unit 110 outputs a high level protection signal Prot, and the transistor switch 112 is a P-type gold oxygen half field effect transistor, which is in an off state at this time. The cut-off time setting terminal TOF causes the set capacitor Cf to be in a discharged state when the switch SW is turned on, and at this time, the potential on the set capacitor Cf is zero. When the changeover switch SW is turned off, the off-time setting terminal TOF stops discharging the set capacitance Cf. Therefore, the current flowing through the set resistor Rf charges the set capacitor Cf. When the level of the set capacitor Cf rises to a predetermined cutoff level, the off-time setting terminal TOF generates a high-level signal to trigger the SR flip-flop 104 to turn the switch SW again, and simultaneously set the set capacitor Cf to a discharge state. The predetermined cutoff level is lower than the level of the power supply VDD. When the conversion controller 100 encounters any circuit abnormality, for example, the short-circuit/open circuit of the LED module 120, the short-circuit/open circuit/current over-current/cross-over voltage of the switch SW, the protection signal Prot is turned to the low level to make the transistor switch 112 is on. At this time, the potential of the cut-off time setting terminal TOF is pulled to be equal to the level of the power supply VDD, that is, the protection logic level is used as an error signal Fail output. The error signal Fail can be output to other circuits, for example, a power supply circuit (not shown) that supplies the power supply Vin, so that the power supply circuit reduces or stops supplying the power supply Vin.

Of course, other feet can be used for the multifunctional foot of the present invention. For example, if the start pin EN of the conversion controller 100 shown in the third figure is not directly connected to the power pin VD but receives an external start signal separately, one end of the transistor switch 112 of the error generating circuit can be coupled to the ground pin. Bit GD, the other end is coupled to the start pin EN. When the switching controller 100 encounters any circuit abnormality, the protection signal Prot is turned to the low level to turn on the transistor switch 112. At this time, the protection logic level of the pin position EN is zero potential, and the conversion controller 100 is stopped. If the protection judgment level of other circuits is set to a high level, the logic level conversion circuit ST as shown in the second figure can be externally connected to the high level error signal Fail output.

Referring to FIG. 4, a circuit diagram of a conversion controller having a multi-function pin according to a second preferred embodiment of the present invention is used to control a DC-DC conversion circuit to drive a LED module 220. . In this embodiment, the DC-to-DC conversion circuit is a boost conversion circuit, and includes an inductor L, a switch SW, a diode D, a capacitor C, and a current detecting resistor R for inputting an input power. The power of Vin is converted into an output voltage Vout to drive the LED module 220. The current detecting resistor R detects the current of the LED module 220 to generate a current detecting signal Ifb. The conversion controller 200 receives the current detection signal Ifb through a feedback pin FB, and outputs a control signal to control the on and off of the switch SW at a driving pin DR, and the duty cycle of the control signal is based on the current detection. The signal depends on Ifb.

The conversion controller 200 includes an error amplifier 202, an overcurrent comparator 203, an undercurrent comparator 204, an error generating circuit, a pulse width modulation comparator 214, a triangular wave generating circuit 215, a logic driving circuit 216, and A reference voltage generator BG, wherein the error generating circuit includes a protection unit 210 and a transistor switch 212. The inverting input terminal of the error amplifier 202 receives the receiving current detecting signal Ifb through the feedback pin FB, and the non-inverting input terminal receives a reference signal Vr generated by the reference voltage generator BG, and generates an error amplification signal at the output end. . The output of the error amplifier 202 simultaneously passes through a compensation pin The COMP is externally coupled with a compensation capacitor Cc to compensate for the error amplification signal. The triangular wave generating circuit 215 generates a triangular wave signal to the inverting input terminal of the pulse width modulation comparator 214, and the non-inverting input terminal of the pulse width modulation comparator 214 receives the compensated error amplifying signal to generate a pulse width accordingly. The modulation signal is applied to the logic drive circuit 216. The logic driving circuit 216 generates a control signal via the pulse width modulation signal and the dimming signal DDIM received by the dimming pin DIM to output the control signal via the driving pin DR to control the switching switch SW.

The non-inverting input terminal of the overcurrent comparator 203 receives the current detecting signal Ifb through the feedback pin FB, and the inverting input terminal receives an overcurrent reference signal generated by the reference voltage generator BG, and the current detecting signal When the level of the Ifb is higher than the level of the overcurrent reference signal Vocp, an overcurrent protection signal Soc is generated, wherein the level of the overcurrent reference signal Vocp is higher than the level of the reference signal Vr. The generation of the overcurrent protection signal Soc represents that the current of the LED module 220 is improperly increased due to a short circuit or other abnormality and exceeds a predetermined overcurrent determination value. The inverting input terminal of the undercurrent comparator 204 receives the current detecting signal Ifb through the feedback pin FB, and the non-inverting input terminal receives an undercurrent reference signal Vucp generated by the reference voltage generator BG, and detects the current. When the level of the signal Ifb is lower than the level of the undercurrent reference signal Vucp, an undercurrent protection signal Suc is generated, wherein the level of the undercurrent reference signal Vucp is lower than the level of the reference signal Vr. The generation of the undercurrent protection signal Suc represents that the current of the LED module 220 is improperly reduced due to an open circuit or other abnormality and is lower than a predetermined undercurrent determination value. The protection unit 210 is coupled to a protection frequency capacitor Cp through a multi-function MFP to determine a protection frequency for the protection unit 210 to time. When the protection unit 210 receives the undercurrent protection signal Suc and the overcurrent protection signal Soc, the timing starts according to the protection frequency, and the conduction current crystal is continuously generated after any one of the undercurrent protection signal Suc and the overcurrent protection signal Soc continues to be generated for more than a predetermined time. Switch 212. One end of the transistor switch 212 is coupled to the multi-function pin MFP, and the other end is grounded, and the voltage of the protection frequency capacitor Cp is pulled to the protection logic level of zero potential when turned on.

The multi-function pin MFP of the conversion controller 200 can be externally connected with a logic level The conversion circuit ST is used to adjust the protection logic level. The logic level conversion circuit ST includes a transistor switch Mfa and a resistor Rfa, and the transistor switch Mfa and the resistor Rfa are connected in series between the power source VDD and the ground. In this embodiment, the switching controller 200 protects the voltage on the frequency capacitor Cp from oscillating between 3V and 4V in a normal state. Therefore, the transistor switch Mfa at this time is kept turned on, and the potential of the connection point of the transistor switch Mfa and the resistor Rfa is zero potential. When the level of the multi-function pin MFP is pulled down to zero potential, the transistor switch Mfa is turned off, and the potential of the connection point of the transistor switch Mfa and the resistor Rfa rises to the potential of the power source VDD to generate an error signal to other Circuit.

It should be noted that the triangular wave generating circuit 215 of the embodiment receives a synchronization signal through a synchronous pin SYN, so that the conversion controller 200 synchronizes with the synchronization signal. The plurality of conversion controllers 200 can also be connected to each other through the synchronization pin SYN, so that the pulse signal generated by the triangular wave generation circuit 215 is transmitted through the synchronization pin SYN, and the triangular wave generation circuit 215 is accepted according to the synchronization pin SYN. The highest frequency of the pulse signals of the other conversion controllers 200 is synchronized, so that the conversion controller 200 can operate synchronously.

As described above, the present invention fully complies with the three requirements of the patent: novelty, advancement, and industrial applicability. The invention has been described above in terms of the preferred embodiments, and it should be understood by those skilled in the art that the present invention is not intended to limit the scope of the invention. It should be noted that variations and permutations equivalent to those of the embodiments are intended to be included within the scope of the present invention. Therefore, the scope of the invention is defined by the scope of the following claims.

Prior art:

10‧‧‧QX9910 controller

20‧‧‧Lighting diode module

L‧‧‧Inductance

Z‧‧‧Zina diode

SW‧‧‧Toggle switch

R‧‧‧current detecting resistor

Vin‧‧‧Input power supply

Rin‧‧‧ input resistance

Cin‧‧‧ input capacitor

Zin‧‧ input Zener diode

VDD‧‧‧ power supply

VD‧‧‧ power pin

EN‧‧‧Starting position

Rcs‧‧‧Detection resistance

Ccs‧‧‧Detection Capacitance

2‧‧‧ comparator

4‧‧‧SR forward and reverse

6‧‧‧Drive circuit

OFT‧‧‧ fixed cut-off circuit

BG‧‧‧reference voltage generator

Ifb‧‧‧ current detection signal

CS‧‧‧Detection

S‧‧‧Setting end

R‧‧‧Reset

Q‧‧‧output

DR‧‧‧ drive pin

TOF‧‧‧ deadline setting

Rf‧‧‧Set resistor

Cf‧‧‧Set capacitor

this invention:

100, 200‧‧‧ conversion controller

102‧‧‧ comparator

104‧‧‧SR flip-flop

106‧‧‧Drive circuit

110, 210‧‧‧protection unit

112, 212‧‧‧ transistor switch

120, 220‧‧‧Lighting two-body module

202‧‧‧Error amplifier

203‧‧‧Overcurrent comparator

204‧‧‧Underflow comparator

214‧‧‧ Pulse width modulation comparator

215‧‧‧ triangle wave generating circuit

216‧‧‧Logic Drive Circuit

VD‧‧‧ power pin

GD‧‧‧ grounding feet

I1, I2‧‧‧ input pin

O1, O2‧‧‧ output pin

S1, S2‧‧‧ set foot

VDD‧‧‧ power supply

PRO‧‧‧protection unit

M‧‧‧Crystal Switch

Prot‧‧‧ protection signal

ST‧‧‧Logical level conversion circuit

Mfa‧‧•Crystal Switch

Rfa‧‧‧resistance

Fail‧‧‧ error signal

L‧‧‧Inductance

Z‧‧‧Zina diode

SW‧‧‧Toggle switch

R‧‧‧current detecting resistor

Rin‧‧‧ input resistance

Cin‧‧‧ input capacitor

Zin‧‧ input Zener diode

EN‧‧‧Starting position

Rcs‧‧‧Detection resistance

Ccs‧‧‧Detection Capacitance

OFT‧‧‧ fixed cut-off circuit

BG‧‧‧reference voltage generator

CS‧‧‧Detection

Ifb‧‧‧ current detection signal

Vr‧‧‧ reference signal

S‧‧‧Setting end

R‧‧‧Reset

Q‧‧‧output

DR‧‧‧ drive pin

Rf‧‧‧Set resistor

Cf‧‧‧Set capacitor

D‧‧‧ diode

C‧‧‧ capacitor

Vout‧‧‧ output voltage

FB‧‧‧reported foot

COMP‧‧‧Compensation foot

Cc‧‧‧compensation capacitor

DIM‧‧‧ dimming feet

C‧‧‧ capacitor

Vout‧‧‧ output voltage

FB‧‧‧reported foot

COMP‧‧‧Compensation foot

Cc‧‧‧compensation capacitor

DIM‧‧‧ dimming feet

DDIM‧‧‧ dimming signal

Vocp‧‧‧Overcurrent reference signal

Soc‧‧‧Overcurrent protection signal

Vucp‧‧‧ undercurrent reference signal

Suc‧‧‧ undercurrent protection signal

MFP‧‧‧Multifunctional feet

Cp‧‧‧Protection frequency capacitor

SYN‧‧‧ synchronized feet

The first picture shows the circuit diagram of QX9910 produced by Quanxin Electronic Technology Co., Ltd. applied to the LED driving circuit.

The second figure is a circuit diagram of a conversion controller having a multi-function pin according to the present invention.

The third figure is a multifunctional foot position according to a first preferred embodiment of the present invention. A schematic diagram of the circuit of the conversion controller.

The fourth figure is a circuit diagram of a conversion controller having a multi-function pin according to a second preferred embodiment of the present invention.

VD‧‧‧ power pin

GD‧‧‧ grounding feet

I1, I2‧‧‧ input pin

O1, O2‧‧‧ output pin

S1, S2‧‧‧ set foot

VDD‧‧‧ power supply

PRO‧‧‧protection unit

M‧‧‧Crystal Switch

Prot‧‧‧ protection signal

ST‧‧‧Logical level conversion circuit

Mfa‧‧•Crystal Switch

Rfa‧‧‧resistance

Fail‧‧‧ error signal

Claims (9)

A conversion controller includes: a power pin for coupling a power source to receive power required for operation; a ground pin for coupling to ground; at least one input pin for receiving an input signal; at least one The output pin is configured to output a signal; the at least one set pin is configured to set an operation parameter of the conversion controller; and an error generating circuit is coupled to the at least one input pin and one of the at least one set pin The pin is simultaneously configured as a protection output pin; wherein the error generating circuit adjusts the level of the protection output pin to a protection logic level when the conversion controller is in a protection state. The conversion controller of claim 1, further comprising an oscillator coupled to the protection output pin, wherein the oscillator determines one of the generated frequency signals according to an external component of the protection output pin. frequency. The switching controller of claim 2, wherein the error generating circuit is coupled to the oscillator to time the signal according to the frequency signal, and after the switching controller is in the protection state for a predetermined time, the protection is performed. The level of the output pin is adjusted to the protection logic level. The conversion controller of claim 3, wherein the protection output pin is externally connected to a logic level conversion circuit to adjust the protection logic level. The conversion controller of claim 4, wherein the logic level conversion circuit comprises a transistor switch and a resistor, the transistor switch and the resistor being connected in series between the power source and the ground. The conversion controller according to claim 1 is characterized in that the switching DC conversion circuit is controlled to drive a light emitting diode module. The conversion controller according to any one of claims 1 to 6, further comprising a synchronization pin for operating at a synchronization frequency according to a synchronization signal. The conversion controller of claim 6, wherein the conversion controller detects a state of the LED module, and when the LED module is in an open state or a short circuit state, Enter the protection state. The conversion controller of claim 1, wherein the error generating circuit comprises a transistor switch coupled to one of the power pin and the ground pin, and the protection output pin, the error generating circuit The transistor switch is turned on to adjust the level of the protection output pin to the protection logic level.